Question

Ethyl acetate reacts with \(\mathrm{NH}_{2} \mathrm{NHCONH}_{2}\) to form (1) \(\mathrm{CH}_{3} \mathrm{CONHCONHNH}_{2}\) (2) \(\mathrm{CH}_{3} \mathrm{CON}\left(\mathrm{NH}_{2}\right) \mathrm{CONH}_{2}\) (3) \(\mathrm{CH}_{3} \mathrm{CONHNHCONH}_{2}\) (4) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NHNHCONH}_{2}\)

Short answer

Option 2: \(\text{CH}_3\text{CON}(\text{NH}_2)\text{CONH}_2\).

Step-by-step solution

Identify reactants and product

Ethyl acetate has the chemical formula \(\text{CH}_3\text{COOCH}_2\text{CH}_3\) and \(\text{NH}_2\text{NHCONH}_2\) is semicarbazide. The reaction involves forming a new product through a chemical reaction.

Analyze possible reaction mechanisms

Consider the nucleophilic nature of semicarbazide. It is likely to attack the carbonyl carbon in ethyl acetate, leading to a substitution mechanism followed by possible rearrangements or eliminations.

Determine the product structure

Given that semicarbazide attacks the carbonyl carbon in ethyl acetate, expect the formation of an acyl semicarbazide. Check the options provided to understand which structure matches this description.

Compare with given options

(1) \(\text{CH}_3\text{CONHCONHNH}_2\) - This structure does not match the expected acyl semicarbazide product.(2) \(\text{CH}_3\text{CON}(\text{NH}_2)\text{CONH}_2\) - This is the correct structure of an acyl semicarbazide.(3) \(\text{CH}_3\text{CONHNHCONH}_2\) - This structure has a different arrangement.(4) \(\text{CH}_3\text{CH}_2\text{NHNHCONH}_2\) - This structure involves ethyl instead of acetyl.

Conclude the correct answer

The only structure that matches the reactivity and expected product is option 2: \(\text{CH}_3\text{CON}(\text{NH}_2)\text{CONH}_2\).

Key concepts

Nucleophilic Substitution

In this reaction, a nucleophilic substitution occurs. A nucleophile is a molecule or ion that donates an electron pair to form a chemical bond. Semicarbazide acts as the nucleophile due to its electron-rich nitrogen atoms.
When nucleophiles interact with electrophiles (electron-poor species like carbonyl carbons), they can replace a leaving group in the compound. Here, the carbonyl carbon in ethyl acetate is electrophilic because of the oxygen atom pulling electron density away.
This makes the carbon more susceptible to attack by semicarbazide.
Understanding nucleophilic substitution is fundamental in organic chemistry, as it explains how compounds transform through the exchange of functional groups.
Key points to remember include identifying nucleophiles and electrophiles, understanding the nature of the leaving group, and predicting the outcome based on the reactants' properties.
This type of reaction is central to forming new carbon-nitrogen bonds, which are prevalent in many biochemical processes and industrial applications.

Reaction Mechanism

The reaction mechanism describes the step-by-step process by which reactants convert into products.
For ethyl acetate reacting with semicarbazide, the mechanism involves several clear stages:
- **Attack**: The nucleophilic nitrogen on semicarbazide attacks the electrophilic carbonyl carbon in ethyl acetate. This forms a tetrahedral intermediate.
- **Rearrangement**: The intermediate may stabilize through several rearrangements. This step may involve losing and gaining small groups like protons to form a stable structure.
- **Formation of Product**: The final stabilization typically results in the formation of the acyl semicarbazide, where the ethyl group is replaced by the semicarbazide moiety, forming a stable compound known as an acyl semicarbazide.
Overall, mechanisms provide a logical pathway showing the flow of electrons and intermediate structures formed. They help in predicting not just the products but also side products and the conditions needed for the reaction.

Acyl Semicarbazide Formation

Acyl semicarbazide formation is the result of the reaction between ethyl acetate and semicarbazide.
The structure of an acyl semicarbazide typically includes an acyl group (from the acetate) linked to the semicarbazide molecule. For the exercise, the correct product is \(\text{CH}_3\text{CON}(\text{NH}_2)\text{CONH}_2\).
This follows from the nucleophilic substitution process where the carbonyl group in ethyl acetate is substituted by semicarbazide, with the loss of the ethoxy group.
The acyl semicarbazide formed is significant in synthetic chemistry as it can be used in further reactions to synthesize numerous other compounds.
It can also act as a precursor for drug synthesis or in creating polymers for industrial use.
Understanding this formation provides insight into designing and predicting outcomes of organic reactions, emphasizing the importance of mastering functional group transformations.